After a lot of research on here, I believe I've tripped the PDC on my '05 2500. My left trailer turn and brake lights don't work.
I finally attempted the install on a modulite today, and followed the directions. After it was all complete, my running lights on the truck with no trailer hooked up stayed on all the time. The only thing I'm not sure about is whether the 4 pin gets spliced to the factory 4 pin, or to the 7 pin. I spliced into the factory 4 pin. Between the &*@## "death wobble", and now this, I've about had it with Dodge all together, but I'm stuck with this truck for a while. My wife tows horses with it, and it's becoming a full-time job trying to keep this thing safe for her. Does anyone PLEASE have any insight what I've done wrong?!

 

Did you isolate both the 4 and seven on the truck from the factory harness (as in cut it) before you tied into it at the 4 way?

Did your truck blow the trailer fuses several times before the PDC gave out?

 

Thanks CRR. I did not isolate the 4 from the 7. I tapped directly into the OE 4 with the Modulite 4. It's been a couple years, but I think I blew a couple. Now, they all check out.
I forgot to mention, I got a little confused with the Modulite directions. I was able to determine my truck has the "3 wire system", but got confused identifying if the "stop and tail are one circuit", or "stop and tail are one circuit with an additional independent stop". I just picked up the directions at step 10 and identified stop, left, right, and tail and wired to modulite accordingly. Everything worked, except the rear running lights stayed on even w/o a trailer hooked up. I sure appreciate your help. I'm down to taking it in to the *********** and bending over if I can't make this stupid thing work.